Despite early delays, Leighton Contractors (Northern), the Hong Kong-based subsidiary of Australia’s largest construction firm, is moving ahead on its US$235M contract to build the Eagle’s Nest road tunnel with joint venture partner, Kumagai Gumi of Japan.
A Highways Department spokesman said the project is slightly behind schedule after the contractors had to overcome poor ground conditions in one of the drives. “Fortunately, there was no water, it was just poor ground,” he said. The heavily faulted ground was excavated using pipe piles and steel sets.
The twin 2.1km three-lane tunnels, together with a 400m long ventilation adit, are being excavated using drill and blast techniques with a shotcrete lining followed by concrete arches cast in situ. Construction started in October 2003 with 450m of running tunnel and 200m of vent adit completed to date. Leighton said, “breakthrough of the main tunnels is scheduled for the middle of next year.” With the Highways Department reporting the project as 19% complete this October and overall completion planned for April 2007, the project is nearly 10% behind its baseline schedule.
The top section of the 18.5m diameter highway tunnels will be sealed with a concrete ceiling slab to form a roughly 30m2 ventilation channel. Equipment includes five Tamrock Axera drill rigs, three Meyco shotcrete machines, eight Terex 35t articulated dump trucks and Cat 988 wheel loaders for construction and spoil removal.
The tunnel forms part of the Route 8 highway (formerly known as Route 9) between Tsing Yi island and Sha Tin.
